Control circuit for an indicating device



Dec. 24, 1968 H. P. BlRMlNGHAM CONTROL CIRCUIT FOR AN INDICATING DEVICEOriginal Filed June 6, 1957 VOLTAGE ON POINT 28 TIME TIME

INVENTOR HENRY P. BIRMINGHAM ATTORNEY United States Patent 3,418,584CONTROL CIRCUIT FOR AN INDICATING DEVICE Henry P. Birmingham,Washington, D.C. (1311 Gatewood Drive, Alexandria, Va. 22307) Originalapplication June 6, 1957, Ser. No. 664,144, now Patent No. 3,125,976,dated Mar. 24, 1964. Divided and this application Aug. 31, 1959, Ser.No. 837,293

4 Claims. (Cl. 328-143) The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment of any royaltiesthereon or therefor.

This invention relates in general to a signal control circuit and inparticular to a circuit for controlling the signals applied to anindicating device.

The present application is a division of applicants copendingapplication Ser. No. 664,144, filed June 6, 1957, now U.S. Patent No.3,125,976, dated Mar. 24, 1967.

In the prior art there are arrangements for controlling the movement ofa craft by deriving signals that are correlates of craft operation, suchas azimuth, rate of turn, and displacement, combining these signals in alinear manner to obtain a resultant signal, and applying the latter toan indicating device. Since the control units for the craft are selectedfor optimum operation under predetermined conditions, these arrangementshave the disadvantage that the time required to make a change in depthor heading is constant and independent of the magnitude of change. Asubmarine, for example, may be brought under optimum operatingconditions in a 10 degree dive to a 500-foot level. A 50-foot dive wouldrequire a smaller angle, say 1 degree, so that it would takesubstantially the same time to bring the craft down 5 0 or 500 feet. I

Accordingly, it is an object of the present invention to provide acontrol circuit for an indicating device permitting optimum response ofa mobile unit over a wide variety of operating conditions.

Another object is to provide a control circuit for an indicating devicethat will permit a mobile unit to change heading or depth withoutovershooting or hunting.

Another object of the present invention is to provide a control circuitfor an indicating device that will permit execution of a maneuver ofsmaller amplitude, e. g., change in heading, in a shorter period of timethan one of larger amplitude.

Other objects will be readily appreciated as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawing, wherein:

FIGURE 1 is an embodiment of the present invention.

In accordance with the present invention, signals are applied through anonlinear circuit to an indicating device in such a manner that theresponse of the device is uniform until a predetermined point ofoperation when the rate response is greatly increased. The signals maybe correlates of the variables of mobile unit operation.

Referring to FIGURE 1, terminal is connected through resistor 11 andindicating device 12 to ground. Terminals 13 to 16 are connected toadding network 17, the output of which is applied to indicating device12 through resistor 18 and through resistor 19 to unilateral impedancedevices 21 and 22. The unilateral impedance devices are connected ininverse polarity. Network 23, comprising potentiometers 24 and 25 andsources of D.C. potential 26 and 27 connected in series, forms a voltagelimiter since the output of the network is the difference in magnitudebetween the voltage across either potentiometer 24 or 25 and the voltageapplied to the network from adding network 17 through either unilateralimpedance devices 21 or 22. The output of network 23 is applied toindicating device 12.

Patented Dec. 24, 1968 To explain the operation of the embodiment shownin FIGURE 1, reference is made to FIGS. 2 and 3. Assume that bias A, asshown in FIG. 2, is applied by potentiometers 24 and 25 to unilateralimpedance devices 21 and 22. At time Z the bias voltage will be equal tothe voltage applied to point 28 in FIG. 1 by adding network 17. Nowreferring to FIG. 3, the current through indicating device 12, due tothe output of adding network 17, will increase along the slope c untiltime Z when the increased voltage applied to indicating device 12 bynetwork 23 will cause current through the same to increase along sloped.

If the signals applied to terminals 10 and 13 to 16 are correlates ofvariables of submarine operation, they may be representative of depth,craft angle, rate of change of craft angle, stern plane displacement,and stern control wheel displacement, respectively. By varying the biason unilateral impedance devices 21 and 22 it is possible to control thelocation of the break in the curve shown in FIG- URE 3. The position ofthe break will determine the length of time the stern and/or bow planeswill act to develop craft angle, and this in turn will determine in partthe slope the craft will take in moving to a desired level.

Thus, the embodiment of the invention disclosed may be used in theoperation of a submarine to determine the slope of glide from one levelto another. When the planesman or operator desires a certainglide-slope, he merely sets variable resistors 24 and 25 so that theresultant signal derived from adding network 17 must attain apredetermined value before indicating device 12 displays the level towhich the craft is to be brought. It is apparent that, depending uponthe position of the top of the potentiometers 24 and 25, the stern planecontrol wheel and stern planes of the submarine must be displaced to agiven position for a given length of time to permit the resultant signalto build up to the required magnitude. This, in turn, will determine thecraft angle and, consequently, the slope of glide from one level toanother. Hence, by merely adjusting variable resistors 24 and 25 theplanesman can control the slope of the glide in bringing the craft fromone level to another.

Various modifications are contemplated and may obviously be resorted toby those skilled in the art without departing from the spirit and scopeof the invention, as hereinafter defined by the appended claims, as onlya preferred embodiment thereof has been disclosed.

What is claimed is:

1. In a signal control circuit for use in navigating a mobile craft, anindicating device having first and second indicator terminals, meansconnecting said second indicator terminal to ground, a unilateralimpedance device having a first terminal and a second terminal, aplurality of signal sources providing signals having a selectedpotential value correlated to navigation functions of the craft, meansfor connecting said first impedance terminal to the output of some ofthe signal sources and the second impedance terminal to said firstindicator terminal, means for providing a potential having a levelcorresponding to a condition in which navigation control should beexercised, means for connecting said last-mentioned means to said secondimpedance terminal and means for applying the output of other of saidsignal sources directly to the first indicator terminal.

2. In a signal control circuit for use in navigating a mobile craft, anindicating device having a first terminal and a second terminal, meansconnecting said second terminal to ground, a third terminal, a fourthterminal, and a pair of unilateral impedance devices, means connectingsaid pair of unilateral impedance devices between said third terminaland said fourth terminal in inverse polarity, first signal sourcesproviding signals having selected potential values representative ofnavigation functions of the craft, means for connecting said thirdterminal to the out put of some of said first signal sources and saidfourth terminal to the first terminal of said indicating device, meansfor providing a potential having a level corresponding to a condition inwhich navigation control should be exercised, means for connecting saidlast-mentioned means to said fourth terminal, and means for applying theoutput of said signal sources directly to the first terminal of saidindicating device.

3. The signal control circuit set forth in claim 2 includ ing a secondsignal source and means for connecting said second signal sourcedirectly to the first terminal of said indicating device.

4. In a signal control circuit for use in navigating a mobile craft, anindicator device having a first and second terminal, means forconnecting said terminal to ground, a voltage limiter including a firstand second direct current potential source, a first and secondpotentiometer element, and a third terminal connected in series in sucha manner that the first and second direct current potential sources arein the same polarity and said third terminal is located between saidfirst and second potentiometers, a fourth terminal, first and secondunilateral impedance devices, means for connecting said first unilateralimpedance device between said first potentiometer and said fourthterminal and said second unilateral impedance de- References CitedUNITED STATES PATENTS 2,139,467 12/1938 Roosenstein 328171 2,434,9291/1948 Holland et al 328171 2,497,693 2/1950 Shea 328-17l 2,703,3823/1955 Cleary 328171 2,861,185 11/1958 Hopper 328171 RODNEY D. BENNETT,Primary Examiner.

D. C. KAUFMAN, Assistant Examiner.

US. Cl. X.R.

4. IN A SIGNAL CONTROL CIRCUIT FOR USE IN NAVIGATING A MOBILE CRAFT, ANINDICATOR DEVICE HAVING A FIRST AND SECOND TERMINAL, MEANS FORCONNECTING SAID TERMINAL TO GROUND, A VOLTAGE LIMITER INCLUDING A FIRSTAND SECOND DIRECT CURRENT POTENTIAL SOURCE, A FIRST AND SECONDPOTENTIOMETER ELEMENT, AND A THIRD TERMINAL CONNECTED IN SERIES IN SUCHA MANNER THAT THE FIRST AND SECOND DIRECT CURRENT POTENTIAL SOURCES AREIN THE SAME POLARITY AND SAID THIRD TERMINAL IS LOCATED BETWEEN SAIDFIRST AND SECOND POTENTIOMETERS, A FOURTH TERMINAL, FIRST AND SECONDUNILATERAL IMPEDANCE DEVICES, MEANS FOR CONNECTING SAID FIRST UNILATERALIMPEDDANCE DEVICE BETWEEN SAID FIRST POTENTIOMETER AND SAID FOURTHTERMINAL AND SAID SECOND UNILATERAL IMPEDANCE DEVICE BETWEEN SAID SECONDPOTENTIOMETER AND SAID FOURTH TERMINAL SO THAT SAID FIRST AND SECONDUNILATERAL IMPEDANCE DEVICES ARE IN INVERSE POLARITY, MEANS FORCONNECTING SAID THIRD TERMINAL TO THE FIRST TERMINAL OF SAID INDICATINGDEVICE, A SOURCE OF SIGNALS REPRESENTATIVE OF NAVIGATION FUNCTIONS OFTHE CRAFT, MEANS FOR CONNECTING THE OUTPUT OF SAID SOURCE OF SIGNALS TOSAID FOURTH TERMINAL AND MEANS FOR APPLYING OTHER SIGNALS OF SAID SOURCEOF SIGNALS DIRECTLY TO THE FIRST TERMINAL OF SAID INDICATING DEVICE.